.travis.yml in jbuilder-2.7.0 vs .travis.yml in jbuilder-2.8.0

@@ -1,27 +1,27 @@
 language: ruby
 
 sudo: false
 cache: bundler
 
+before_install:
+  - gem update --system
+  - gem install bundler
+
 rvm:
   - 1.9
   - 2.0
   - 2.1
-  - 2.2.5
-  - 2.3.1
-  - 2.4.0
+  - 2.2.10
+  - 2.3.7
+  - 2.4.4
+  - 2.5.1
   - ruby-head
   - jruby-19mode
   - rbx
 
 gemfile:
-  - gemfiles/rails_3_0.gemfile
-  - gemfiles/rails_3_1.gemfile
-  - gemfiles/rails_3_2.gemfile
-  - gemfiles/rails_4_0.gemfile
-  - gemfiles/rails_4_1.gemfile
   - gemfiles/rails_4_2.gemfile
   - gemfiles/rails_5_0.gemfile
   - gemfiles/rails_5_1.gemfile
 
 matrix:
@@ -49,18 +49,8 @@
       gemfile: gemfiles/rails_5_1.gemfile
     - rvm: rbx
       gemfile: gemfiles/rails_5_0.gemfile
     - rvm: rbx
       gemfile: gemfiles/rails_5_1.gemfile
-    - rvm: 2.4.0
-      gemfile: gemfiles/rails_3_0.gemfile
-    - rvm: 2.4.0
-      gemfile: gemfiles/rails_3_1.gemfile
-    - rvm: 2.4.0
-      gemfile: gemfiles/rails_3_2.gemfile
-    - rvm: 2.4.0
-      gemfile: gemfiles/rails_4_0.gemfile
-    - rvm: 2.4.0
-      gemfile: gemfiles/rails_4_1.gemfile
 
 notifications:
   email: false